Motor-control system



Oct. 13,

G. E. KING MOTOR CONTROL SYSTEM Filed Feb. 8, 1923 ATTORNEY Patented Oct. 13, 1925.

UNITED STATES PATENT OFFICE.

GEORGE E. KING, OF WILKINSBUBG, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

MOTOR-CONTROL SYSTEM.

Application filed February 8, 1923. Serial No. 617,735.

To all whom it may concern:

Be it known that I, GEORGE E. KING, a citizen of the United States, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Motor-Control Systems, of which the following is a specification.

My invention relates to systems of motor control and it has particular relation to such systems as are employed in connection with machine-tools and the like.

The object of my invention is to automatically control the relative operations of a plurality of motors.

In many motor applications, it is possible to increase the efficiency of the work done and also to increase the production by maintaining a definite sequence of operation. It is also possible for a single operator to give adequate attention to a number of automatic machines and this procedure has become common in modern manufacturing plants.

My invention will be best understood with reference to the accompanying drawing, in which the single figure is a diagrammatic view of circuits and apparatus embodying my invention.

A motor having an armature 1 and a shunt field-magnet winding 2 may be operatively connected through reversing switches 3 and 4, to a source of energy comprising line conductors 5 and 6. A starting resistor 7 is controlled in a familiar manner by means of an accelerating switch 8. The direction of operation of the motor armature is controlled by a master switch 9, which has been illustrated as of a type described in United States Patent 1,241,510, granted to E. A. Hanfi' and assigned to the \Vestinghouse Electric. & Manufacturing Company. A plurality of interlocks 11 and 12 are mechanically attached to, and operated respectively by, switches 3 and 4. A no-voltage relay 13 is controlled by a push-button switch 14.

Electrically interlocked and co-operating with the foregoing apparatus is a substantially duplicate equipment comprising a mo tor having an armature 21 and a shunt fieldniagnet winding 22, and which is operatively connected, through a pair of reversing switches 23 and 24, to line conductors 5 and 6. An accelerating resistor 27 is controlled by an accelerating switch 28, and a master switch 29 is provided for effecting the operation of reversing switches 23 and 24. Interlocks 31 and 32 are respectively connected to, and actuated by switches 23 and 24, and the operation of a no-voltage relay 33 is effected by means of a push-button switch 34.

According to my invention, either of the motors may be operated and its direction of rotation may be reversed, at will, provided that the master switch governing the other motor occupies its illustrated and inoperative position. For example, when master switch 29 occupies its illustrated position, master switch 9 may be actuated to control reversing switches 3 and 4 in the following manner. No-voltage relay 13 is first closed by momentarily actuating push-button 14, whereby a circuit is established from line conductor 5 through switch 14 and operating coil of relay 13 to line conductor 6. A holding circuit for relay 13 extends from line conductor 5 through conductor 36, relay 13, after its closure, and coil 35 to line con ductor G. Vhen master switch 9 is actuated to the right, a circuit is established from conductor 5 through conductor 36, relay 13, conductor 37, switches 38 and 39, conductor 40, coil 41 of reversing switch 4, conductor 42, switch 43 and conductor 44 to line conductor 6. Reversing switch 4 then closes to operate the armature 1 in a direction that will be assumed as the forward direction of operation.

lVhen it is desired to reverse the armature 1., master switch 9 is actuated to the left to open switch 4 and to establish a circuit from line conductor 5 through conductor 36, relay 13, conductor 37, switches 45 and 46, conductor 47, coil 48 of reversing switch 3, conductor 49, switch 50 and conductor 44 to line conductor 6. Reversing switch 3 then closes to establish the reverse direction of operation of armature 1. It is manifest that since the operating coils 41 and 48 of switches 4 and 3, respectively, are fed through switches 43 and 50 of master switch 29, armature 1 cannot be controlled at will unless master switch 29 occupies its illus trated inoperative position.

However, armatures 1 and 21 may be simultaneously operated in a given direction corresponding, for example, to the righthand positions of master switches 9 and =fnem'1ine conductor 5 thro In these positions, reversing switch 4 is closed and a circuit -for operating coil 41 thereof extends, as previously "traced, through switch 43 of master switch 29. In the right-hand position of master switch 29, switch 43 is closed and switch 50 is 0 en. Also, switches 51 and 52 are closed. en no-voltage relay 33 is closed b means of switch 34, it is normally retained closed, since it is controlled in o. nmncr simihu' to relay 13. In addition, a circuit extends ugh relay 33, condoctor 53, switches 52 and 51, conductor 54, coil 55 of'revensing'swwitch 24, conductor 56, switch 57 and conductor 58 to line condoctor 6. Reversing switch 24 is, therefore,

closed to establish iconnections'for the operation of armatm 21. Armatures 1 and 21 are now rotating in iven directions corresponding to the right-hand operation of master switchesl) and 29.

At lthe end of a certain niod, master switch 9 may be automatical returned to its illustrated position and armature 1 brought to rest. Master switch 9'nny be reversed, that is, moved to its left-hmd position, but armature 1 is in no-wise afiected thereby until armature 21 has completed its operation, when master switch 29 is returned to either'its ofi position or. is reversed.

After the circuit of armature 1 is interrupted, and duringthe continued operation of armature 21, a circuit for theo ting coil 55-of reversing switch 24, is maintained independent] of the position of master switch 9. T t .is, whenmaster switch 29 occupies its right-hand position, a. circuit for coil 55-extends from line conductor 5 through relay 38, conductor 53, switches 52 and 51, conductor 54, coil 55and interlock 32 to line conductor 6. As'soon as master switch 29'is returned either to its-illustrated or to-its reversed position, switches 51 and 52 are opened and coil 55 becomes-dieenergi-zcd. W

A'rmature 1 may now be operated in a reversed direction whenever master switch 9:is actuated tothe left and whenever master switch 29 occupies-its illustrated position, or whenever it occupies its reversed or lefthend position. Reversing-switch 3 is now closed by its operating coil 48, a-circuit for which was'previeusly traced and which-extends through switch 50of master switch 29, which is closed when this master switch occupies itslett-hand pcsition, in which position switch 43'is'open. Armatures '1 and 21 may continue to operate for a predetermined period and when either master switch is again returned to itself position or is reversed, the other motor is notnflected until its corresponding master switch is actuated. Armature 1, e. g., may complete its operation independently of master "switch 29, but it may not be reversed prior to areversal oi-armature-2L The holding circuit formil 48 of. rcvensingswiich 3, which circuit is independent of master switch 29, extends from line conductor .5 through com ductor '36, relay I3, conductor37, switches 4'5 and '46, conductor 4'7, coil 48 and interloek 11-to-line conductor 6. Therefore, until" switches 45 and 46 of master switch 9 are OPMYWWI'B1 will continue its operation.

Similarly, a holding circuit tier hcoil 59 clf reversing switch '23extends line-conductor 5 through relay 33, condom 53, switches 60 and 61, conductor '02, coil 5'18!) and interlockfiltoline conductor 6. fore, switch 23 wlllremain closed and ammture 21 will continue to operate indepmd ently of the position of mader switch until mitchesaw and 6105mm switch are opened. From the fcrcgoinp'damipticmit-is Parent that a Piurc mctomc :n .t cordingto my invention may be operated in,

a given direction for performing Mayne-MW sired work, such as is re uired'of planem orr other machine tools, an neither motor can be reversed until the-other motor-has plcted its corresponding operation. in

cordance with common practice, it is' i. If slumed that the maesgr M388 32pm t e motors are m anic o a t. any desired movable element oflthe machintool equipment. According to wellknown machine tool operations, the master-switches in the present instance are independemly actuated and it is thepmpcse at m 'im ftion to iplrovide means f0t mntrol the motors independently of the mastzcr swrtclm until 'the completion at Tm machine -o. It is 'ior fln; mctoretohesiniultmcously ino I pos' dinections, and, 1; J ore, Ia contain desir ie sequence of o tions of the ma? chines'may foe automatically maintained.

I chim as my invention:

1. The cmhination with n plurality of motions and controlling meme financier, of means for effecting the simultaneous opention of themotorgcach in a given direction, and means for reversal of end 1 motor nior'to'reversalof'anctlrer.

2. e combination with a plurality lof. motors and 'controlling-meanstherefcr, ot. means forfefiecting the simuhnneom open- 5 tion of tlre motors,-eachin= a'given direction. means for preventing reversal of one priorto reversal'ofanother and means "1hr etfectimg operation-octane meter when another isidle.

3. The combination with mpair of more and controlling means therefor, of means for effecting the simultaneous operation-of the motors, each in a given direction, and means for insuring the completion of the operation of each motor, for a predetermined period prior to simultaneously beginning new operations.

4. The combination with a pair of motors and controlling means therefor, of means for effecting the simultaneous operation of the motors, each in a given direction, means for insuring the completion of the o eration of each motor for a predetermined period prior to simultaneously beginning new operations, and means for effecting operation of one motor when the other is idle.

5. The combination with a plurality of motors and controlling means therefor, of means comprising a pair of master switches for effecting the simultaneous operation of the motors, each in a given direction, and for preventing reversal of one motor prior to reversal of another.

In testimony whereof, I have hereunto subscribed my name this first day of February 1923.

GEORGE E. KING. 

